Reinforced concrete construction.



EQSMULSK'L- REINFORCED CONCRETE CONSTRUCTION.

APPLICATION FILED IAN-8. l9l3.

1,154 %8. Patented Sept. 21, 1915.

'izfzflbgss es. 1711067113071 52 I Edward 37nd Zski. 43%;; N 9 u j Specification of Letters Patent. Y

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Patented Sept. 21, 1915.

- Application filed January 8, 1913. SeriaINo. 740,763.

- Y To-dll wiio mit may concern i x 1 -,Be itknownthat I, EDWARDSMU'LSK-I, a {subject of the Emperor of Austria-Hungary,

anda-resident of-Newton Highlands, county of Middlesex, State of Massachusetts,

(whosepost-officev address is 809 Oliver Building, Boston,,Massachusetts,) have 1nvented an ImprovementjnReinforced Con- -crete Construction, of'whrch the following 'dGSCIlPlJlOIL, in-c0nne'ct1on w1th the a'ccomfpanying'drawings, is a specification, like characters on theqdrawingsrepres tin lik -.parts.

This invention'rel-at'es to reinforced concrete construction consisting more particu-' l'arlyv of an improved system of reinforcement for slabs and especially floor slabs.

- The invention will be best understood by .reference to the'following description when taken in connection with the accompanying llustration of one specific embodiment thereof, while its scope willbe more particularly pointed out in :the appended claims.

In the drawings, Figure -1 is a plan View of the system of reinforcement whichmay -be employed in a floor slab embodying one form of my invention; Fig; 2 is a sectional 1 elevation taken on the 1i'ne'2 2'in F ig. 1;

'. :bodiment of myinvention there submitted for i-llustratlve purposes, while the latter may be app-liedto a' slab of non-uniformand Fig. 3 is a similar "sectional elevation taken on theline 33 inFig. l. I

, Referring to the. drawings and to the em- ;thickness, or to a ,slab. which is indented or hasportions cutout, I have herein shown ,"the sameas applied to a flat floor slab l ofuniform; thickness supported by columns 2 -,having the flaring caps 3 and having no beams orgirders The reinforcement for the'slabisarranged n such a waythat the ;direc tion of the reinforcing members coin cides with the direction of the stresses in the slab. The reinforcing members are concentrated at points of greatest stress and their size and number depend upon the magnitude of the bending moment.

Referring to the drawing, and particui larly toFigs. l and 2, the floorslab immediately oyer each column is provided with a ser es of reinforcing members 4 radiating or -diverging from the-axis of the column.

These may be of any suitable material or. shape, but are preferably in the form of'steel rods. These rods diverge from the column adjacent the upper surface of the slab so that they bending moment of the slab.

The full strength of the rods may be developed by a bond between the steel and concrete or by anchoring the inner end of each rod. I For this purpose. any suitable anchorageformation may be provided upon the rods as by, bending over the inner ends thereof. As shownin the draivingsythe rods are carried over the top of the column and each rod is bent thereat into the form of a suitably shaped and proportioned book. The inner ends of the rods may be attached to each other or to a common anchorage member, such member being herein provided by the ring 5' with which the hooked ends of the radial rods engage. Thebeut end 6 of each rod may be prolonged as shown so as to extend adjac'ent 'the lower surface of the slab'and serveas compression reinforce Inent thereat. The weight of the slab or a" load'thereon produces a strong compression in the region of the'concrete atthe juncture ofthe slab with the column tending to rupture or 1n ure the concrete in said region.

omen. r

- .hDWARnsrfU- sm, or NEWTON HIGHLANDS, MASSACHUSETTS.

take the tensile'stress due to the This, however, is efi'ectively preventedrbv the presence therein of the bent ends 6 of said rods. The purpose of the inner ring 5is primarily to keep the inner ends of the radial bars in. position during concreting and also to add an additional factor of safety by of maximumstress, that is the edge of the column head, a sufficient distance to develop in combination with the hook the full strength-of the bar and the stress of the hooked bars is directly transferred to the concrete by bond and bearing. I In designing the inner rings are arranged in such a vxav that the radial bars are not relied upon until their full strengthis developed by embedment in the concrete and the hook.

The radial rods 4 are designed to resist the radial bending moment of the slab. To resist the circumferential moment, circumferential reinforcing" members 7 are oro' vlded transverse the radial members ixaiid' also near the upper surface of the slab. The

- form of straight rods, but herein are shown as annular or circumferentidl in form.

from a central or intermediate point in the panel, and preferably substantially the point of greatest stress, toward the reinforcementat and above the adjacent columns. The panel reinforcement is located near the lower face ofthe slab as shown so as properly to take the tensile stress thereat. The panel reinforcing rods 8 are also securely anchored near the center of the panel so as to develop their full strength. Their anchorage may be provided in any desired manner, but herein their inner ends are bent each into the form of a hook 9 and caused to engage a-n anchoring ring 10, which latter securely holds them in position. The other end of each rod may be straight or bent and carried into the upper part of the slab if desired.

In order to resist circumferential mioments in the slab transverse reinforcing members are employed, also near the lower surface of the slab. At. the left of Fig. -1 theseare shown to consist of'circumfe'rential rods 11 combined with straight rods 12, but instead of the circumferential rods,

straight rods 13 may be used as shown at the right of Fig. 1. The size and number of the reinforcing members in each case will, of

course, be designedwith reference to the magnitude ofthe bending -moment to be encountered. By diverging reinforcing members I do not necessarily mean those which are arranged in a true radial relation, but intend to includes'uch an arrangement of reinforcement as tendsto concentrate the same near the point of greatest stress in the panel. r

The described form of reinforcement possesses great advantages over forms heretofore prevailing. A surplus of metal is avoided since the rods occur only where needed and in the amount needed. That is to say, their diverging arrangement naturally concentrates them at points of greatest stress. The principal bars being arranged in one layer only, the effective depth of a slab having a given thickness is greater than where multiple layers are employed. Furthermore. the total sectional area of the steel is eflective in resisting the stresses.

As indicated in the drawings, the ring 5 is preferably larger than the diameter of the column so as to leave at the column an open space between the slab reinforcement and the column reinforcement. The purpose of this is to permit the cleaning of the column head form after the concrete in the column has been poured. It is a Well known fact that the. top of the concrete after setting becomes covered with scum and laitance, or decomposed cement. Other impurities and dirt also find their way into the column head form in the interval between placing the steel andpouring the slab concrete. For good work the laitance and impurities should be removed. In systems where a 'mesh of bars is placed over the column or where reinforcements extend as far as the column steel, cleaning of the column formwork is difiicult if not impossible. In the disclosed system, the form-work is easily I accessible and .no difficulty is encountered from cleaning. The disclosed system also requires less steel since every radial bar is shorter by the difference in the radius of the circuit around which they stop and the radius of the column.

While I have herein shown and described for purposes of illustration one specific form of the invention and applied to a floor slab, it is to be understood that the same is not limited to the details of construction and specific form and relative arrangement of parts herein described, or to its application to a floor slab, but that it may be applied to constructions other than floor slabs, and extensive deviations may be made from the illustrative embodiment without departing from the spirit of the invention.

Claims.

1. In a concrete. slab construction, the combination with asupporting column of reinforcing members diverging from the axis of the column, each of said members having a reverse bend near the column and presenting a portion near the upper surface of the slab, and a portion near the lower surface of the slab extending across and serving as a compression reinforcement for the juncture of the slab with the column.

2. Ina concrete slab construction, the combination with a supporting column of reinforcing members diverging from the axis of the column, each of said members having a reverse bend near the column and presenting a. tension reinforcement near the upper surface of the slab, and acompression reinforcement portion near the lower surface of the slab, said reverse bend having a depth substantially greater than the thickness of the member for anchoring the same with extensive bond and bearing in the concrete.

3. In a concrete slab construction, the combination with a supporting column of reinforcing members diverging from the axis of the column, each of said members having a reverse bend near the column and presenting a tension reinforcement portion near the upper surface of the slab, and a prolonged compression reinforcement portion near the lower surface of the slab.

4. In a concrete slab construction, the combination with a supporting column of reinforcing members diverging from the 6 'of the slab and a portion near the lower surface of the slab extending across and serving as a compression reinforcement for the juncture of the slab with the column; and other reinforcing members arranged transversely of said diverging members and circumferentially of said column axis.

5. In concrete"construction, the combination with supporting columns, of an intermediate slab, reinforcing members in said slab diverging o he axis of. the column, each of said here having a reverse bend near the 001m and presenting tension and compression p0 ions near the upper and lower surfaces, sp'e'ctively of the slab and prolonged away "from said column; other reinforcing members arranged transversely of said diverging members and circumferentially of said column axis; a series of reinforcing members diverging from a central point in said slab between said columns and reinforcing members arranged transversely of said diverging members and circumferential ly of said central point.

6. In concrete construction, the combination with supporting columns, of an mediate slab, reinforcing members in' sat slab diverging from the axis of the column,

v each of said members having a reverse bend near the column and presenting a portion near the upper surface of the slab, and a portion near the lower surface of the slab extending across and serving as a compression reinforcement for the juncture of the slab with the column; other reinforcing members arranged transversely of said diverging members and circumferentially of said column axis; a series of reinforcing members diverging from the central point in said slab between said columns and reinforcing members arranged transversely of said diverging members and circumferentially of said central point.

7. In a concrete slab construction, the combination with supporting columns, of an intermediate panel, a series of reinforcing members near the upper surface of the slab diverging from the axis of the column, means for anchoring the inner ends of said members comprising an anchoring ring with which the bent ends of the members engage, the-bent end of each member be ing prolonged adjacent the lower surface of the slab to serve as compression reinforcement, other reinforcing members arranged transversely to said diverging members and circumferentially of said colunm axis, a series of reinforcing members diverging from a central point in the panel and arranged near the lower surface of the slab, means foranchoring the inner ends'of said last named members comprising an anchorng ring engaging the bent over ends on the members, and reinforcing members ar-' .ranged transversely to the diverging members.

In testimony'whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

EDIVARD SMULSKI.

Witnesses JOHN R. LIOULTONP THOMAS E. BOOTH. 

